The invention relates to an apparatus for and a method of heating semiconductor devices. The heating apparatus of semiconductor devices is provided, e.g. in a high temperature handler and it heats semiconductor devices to measure electronic characteristics in a high temperature environment.
The heating apparatus of semiconductor devices is provided in a high temperature handler and heats devices under test (hereinafter referred to as DUT) to an intended temperature in advance so as to measure electric characteristics of the semiconductor devices in a high temperature environment. The structure of a conventional heating apparatus of semiconductor devices is described next with reference to FIG. 3 and FIG. 4. FIG. 3 is a plan view showing the conventional heating apparatus of semiconductor devices, and FIG. 4 is a sectional view of FIG. 3, wherein depicted by 10 is a DUT, 20 is a hand, 30 is a heat plate, 40 is a heat block, 41 is a heater and 42 is a heat insulation wall.
In FIGS. 3 and 4, plural recesses are formed on the upper surface of the heat plate 30 in transverse directions. Each DUT 10 is placed on one of the plural recesses. The heat plate 30 is disposed on the heat block 40. The heater 41 is built in the heat block 40. If the heater 41 is energized or turned on in a state where each DUT 10 is placed on the heat plate 30, each DUT 10 is heated via the heat plate 30 owing to heat conduction. The heat plate 30 is adjusted in constant heat distribution so that each DUT 10 is heated uniformly. Each DUT 10 which is heated to an intended temperature is moved from the heat plate 30 by the hand 20. Meanwhile, in the heating apparatus of semiconductor devices, the heat insulation wall 42 is provided on the outer side of the heat block 40 to prevent the heat release from the heater 41.
Another conventional heating apparatus of semiconductor devices is shown in FIG. 5 and FIG. 6. FIG. 5 is a plan view showing the conventional heating apparatus of semiconductor devices, and FIG. 6. is a sectional view of FIG. 5, wherein depicted by 11a is a DUT before it is heated, 11b is a DUT after it was heated, 21 is a hand, 31 is carriers, 43 is a heating chamber, and 44 is a heat insulation wall. In FIGS. 5 and 6, the interior of the heating chamber 43 covered with the heat insulation wall 44 is kept at a given temperature by circulating hot air. Each carrier 31 capable of holding four pieces of DUT circulates and moves inside the heating chamber 43. The DUT 11a before it is heated is placed on the carrier 31 by the hand 21. The DUT placed on the carrier 31 is heated to an intended temperature while the carrier 31 moves inside the heating chamber 43, and the heated DUT 11b is removed from the carrier 31 by the hand 21 at a housing position shown in FIG. 5.
In the conventional heating apparatuses of semiconductor devices as set forth above, it takes about slightly below 60 seconds to about 180 seconds for heating, e.g. a package type DUT from a room temperature to 125xc2x0 C.
In the case of a DUT which takes a relatively long time to be measured, it is possible to secure time to heat the DUT sufficiently utilizing measuring time as standby time so that a volume of a preheating chamber may be reduced. However, in the case of a DUT which takes a relatively short time to be measured, it is necessary to increase the volume of the heating chamber for heating a next DUT to an intended temperature while the heated DUT is measured. Accordingly, in the case of a DUT which takes a relatively short time to be measured, it is not avoidable that the heating apparatus becomes large sized and also the entire handler becomes large sized and a cost for increasing power supply capacity to heat the heating apparatus increases. This becomes more eminent if the throughput of an autohandler is improved by increasing the number of parallel measurements.
An autohandler has been required to cope with a variety of shapes of packages. It is necessary to prepare a variety of heat plates 30 or carriers 31 in accordance with a variety of shapes of packages according to the conventional heating apparatuses of semiconductor devices, causing a problem of convenience and cost thereof.
The invention has been developed to solve or at least minimize the foregoing problems, and has an object to provide a heating apparatus for semiconductor devices capable of coping with a variety of DUT packages with low cost, and of restraining the heating apparatus for semiconductor devices from being large sized and of minimizing the increase of power supply capacity.
To achieve the above object, the invention employs first means comprising plural trays on which multiple semiconductor devices are mounted, a heating chamber having plural stages in which each tray is housed, and a tray moving mechanism for moving each tray inside and outside the heating chamber.
The invention has second means wherein each tray in the first means is standardized and the tray moving mechanism has plural plates for holding and placing the plural trays thereon.
The invention has third means wherein the first or second means further has heat units for keeping the semiconductor devices warm at an intended temperature, wherein the semiconductor devices are moved from inside the heating chamber to outside thereof in a state where they are placed on each tray.
The invention has fourth means wherein the heat units in the third means have a blower for blowing hot air toward the semiconductor devices.
The invention also comprises a method of heating semiconductor devices in a heating apparatus for semiconductor devices including plural trays on which multiple semiconductor devices are mounted, a heating chamber having plural stages in each of which a tray is housed, and a tray moving mechanism for moving each tray into and out of the heating chamber, wherein the method comprises a supplying step for supplying semiconductor devices on each tray, a heating step for heating the semiconductor devices supplied on each tray to an intended temperature, a step for relocating and measuring the semiconductor devices which are heated in the heating step from each tray, wherein these steps are repeated, and wherein the supplying step and the relocating and measuring step relative to the other tray are completed during the heating step relative to the one tray.